Such sound transducer assemblies are installed, for example, in mobile phones or hearing aids. The term “MEMS” stands for microelectromechanical system. A MEMS sound transducer with a carrier substrate made of silicon, a hollow space formed in the carrier substrate and a multi-layer piezoelectric membrane structure is known, for example, from DE 10 2013 114 826 A1, aka U.S. Patent Application Publication No. 2017-0006381, which is hereby incorporated herein by this reference for all purposes. The hollow space described in this document features at least one opening that is spanned by the multi-layer piezoelectric membrane structure. In its edge area, the membrane structure is connected to the carrier substrate, which consists of silicon, such that, in order to generate and/or detect sound energy, the membrane is capable of oscillating relative to the carrier substrate. A major disadvantage of such silicon-based MEMS sound transducers is the very high manufacturing costs, since silicon (in particular) is very expensive compared to other materials. In addition, the size of the piezoelectric membrane structure, on the one hand, should be as large as possible, in order to be able to generate a high sound pressure. On the other hand, due to the expensive piezoelectric components, the membrane structure should be as small as possible, in order to reduce manufacturing costs. An additional disadvantage is that such a MEMS sound transducer or such a silicon substrate is used in conjunction with a printed circuit board, which together feature a relatively large construction volume. Its field of application is limited, because it can only be installed in devices that provide a correspondingly large installation space.